Diaphragm and mounting therefor



Nov. 13, 1928. 1,691,093

I E. TOMAN DIAPHRAGM AND MOUNTING THEREFOR Filed April 21, 1926 L MUM)!" Patented Nov. 13, 1 928." I I 1 UNITED] ATESQ PATIENT o- FFICE. Y

EDWARD roman, or CHICAGO, ILLINoIs, ASSIGNOR r E. TOMAN & COMPANY, or

' CHICAGO, ILLINOIS, acoaroaarron or ILLINOIS. a

, IAPHRAGM ANIDQMOUNTING THEREFOR. I

1 Application med an 1e2 m no. icsnzs.

This invention relates to a diaphrag'm and mounting therefor and particularly to a dia; phra'gm. structure which is adapted to-be used in connection with phonograph repro? ducers, radio loud speakers and ,similar in struments in the reproductionand ampl ficationof audible sound waves,

An important object of this invention resides in the'provisionof a diaphragm the entire surface of which is vibratable in such a manner as to effectively reproduce sounds throughout the audible range with a maximum of efliciency. I I

It is a further important object offthls inventionto provide areproducing instrument ofthe kind'described which isstrong and durable, which does not easily get out of adjustment, and which may be GCOIIOIXllCfLL 1y manufactured.

Otherand further important objects of this invention will be apparent from the disclosures in the specification and accompanying drawings;

illustrated on the drawings and hereinafter more fully described.

On the drawings: I Figure 1 is aside elevation of the phono graph reproducer provided with the d aphragm and mounting embodying the prinq ciples of this invention. I i

Figure 2 is a section on the line I I-II of Figure 1. I I I Figure 3 is a plan view of the reproducer unit with the back plate removed, I

Figure 4 is. an enlarged fragmentary detail sectional view illustrating the method of I supporting the diaphragm.

As shown on the drawings:

I The reference numeral 1 indicates an an nular plate which forms the base of the re producer and which maybe provided with an integral sound outlet portion communieating with a tone'arm 3 ofusual construction. The diaphragm of ,thisinvention com-' prises a disk 4, which may be made of any suitable material but which I have found gives particularly good results when comstructed of a magnesium alloy. Said diaphragm i is held in position relative to the I plate 1 by means of a flanged clamping ring 5 i which is secured to said plate 1 by screws 6 and which serves to position two cushion supporting members 7 which are constructed The invention (in preferred form) isofrubbe'r composition or other suitableresilient cushioning materialand which engage only the extreme edge of the ma or"port1on of the diaphragm as will be evident from Figure 4. I

In order tofacilitate assembly of the diaphragmnwithiii the clamping ring 5 andto properly center the same, saiddiaphragm' is 1 provided with three integral radial prongs 8 which are relatively narrow so thatthey only comprise a very small percentage of the periphery of the diaphragm. By mounting the diaphragm-as just described wherein only the extreme edge thereof engages the cushion supporting means, it is possible to'readily vibrate'the entire surface of the diaphragm including the extreme edgethereof without undue resistance or damping and thus accutegralbosses 9 in which a stylus bar 10 is pivotally mounted, one end of said stylus bar carrying areproduccr arm 11 secured to the center of the'diaphragm 4 and the other end being provided to removably carry a usual phonograph needle or other suitable stylus 12. Thus vibrationsof said stylus 12 are transmitted through the arm 11 to the diaphragm Where they are faithfully reproduced. g I I By the construction of this invention-it is possibleto employa diaphragm of consider: able thickness since the edge thereof for all practical purposes is unrestrained and allowed to vibrate to faithfully "reproduce notes or sounds low in the scale. I have found it preferable to so mount the diaphragm relative tothe cushioning means 7 as to only engage the extreme edge thereof, and within certain limits, this engagement of the cushioning means with the surface of the diaphragm should be as little as possible, for example, certain experiments which I have made indicate that the engagement of the cushioning means over the surface of the diaphragm should not be for a distance of more than three times the thickness of the diaphragm and preferably much less.

\Vhile I have shown and described the diaphragm of this invention for use in connection with a phonograph reproducer, it will be apparent that it might be used without modification in similar sound reproducing instruments such as radio loud speakers wherein the diaphragm mounting would be the same as shown, with standard means attached thereto to efiect the vibrations. I

I am aware that numerous details of construction may be varied through a wide range without departing from the principles of this invention, and I therefore do not intend limiting the patent granted, otherwise than necessitated by the priorart.

I claim as my invention:

In a device of the class described, an annular easing having an internal flange, a ring of resilient material on the flange, diaphragm positioning means, a diaphragm positioned on said ring so that only the extreme edge of the ably position said'diaphragm and to substan tially prevent lateral displacement of said diaphragm in said casing.

In testimony whereof I have hereunto subscribed my name.

EDWARD 'IVOMAN. 

